i had this problem a month ago. after reading up code and discussing =
with Rui Paulo,
i increased the number of mbuf clusters and it apparently went away. i =
can't really
precise if it's really that correlated but try it and give some feedback =
here again.

>The only uncommon thing about the machine in question is that it has =
two
>network interfaces connected to the same ``wire''. We run two IP nets
>(131.220.120/24 and 131.220.146/24) on the same ethernet (until I find =
the
>time to partition the switches) and this was the way to make DHCP work.

My machine had two interfaces too, one crossed-over to a cisco router =
and another
one on a huge broadcast domain. both interfaces have alot (10+) ip =
aliases and=20
they both are gateways for 1000+ other hosts. (i know, horrible =
topology.)

the only reference to this kind of problem i found on the web was some =
guy with
a sun sparcstation (or was it an ultra) and no one gave feedback.

best regards,
Francisco Guerreiro